Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.4 (RNase H)
 2,751 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In addition to the two usual eukaryotic elongation factors (EF-1 alpha and EF-2) fungal ribosomes need a third protein, elongation factor 3, for translation. EF-3 is essential for in vivo and in vitro protein synthesis. Functionally, EF-3 stimulates EF-1 alpha dependent binding of aminoacyl-tRNA to the ribosomal A site when E site is occupied by deacylated tRNA. EF-3 has intrinsic ATPase activity which is regulated by the functional state of the ribosome. EF-3 ATPase is activated by both 40S and 60S ribosomal subunits. However intact 80S ribosomes are needed for efficient activation of EF-3 ATPase. EF-3 appears to be an RNA binding protein with high affinity for polynucleotides containing guanosine rich sequences. To determine whether guanosine rich sequence of ribosomal RNA is involved in EF-3 binding, an antisense oligonucleotide dC6 was used to block EF-3 interaction with the ribosome. The oligonucleotide suppresses activation of EF-3 ATPase by 40S ribosomal subunit and not by the 60S or the 80S particles. Poly(U)-directed polyphenylalanine synthesis by yeast ribosomes is inhibited by dC6. To define the binding site of the oligonucleotide and presumably of EF-3 on 18S ribosomal RNA, hydrolysis of rRNA by RNase H was followed in the presence of dC6. These experiments reveal an RNase H cleavage site at 1094GGGGGG1099 sequence of 18S ribosomal RNA. This guanosine rich sequence of rRNA is suggested to be involved in EF-3 binding to yeast ribosome. Data presented in this communication suggest that the activity of EF-3 involved a direct interaction with the guanosine rich sequence of rRNA.
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PMID:Interaction of yeast elongation factor 3 with polynucleotides, ribosomal RNA and ribosomal subunits. 871 1

Sex-determining region Y (SRY)-box protein 2 (SOX2) plays a critical role in stem cell maintenance and carcinogenesis. In addition to its function as a minor-groove DNA binding transcription factor, our previous study showed that SOX2 also acts as a RNA binding protein. In current study, we first showed that SOX2 displayed high affinity toward the mRNA encoding S100A14 in BFTC905 and that depletion of SOX2 resulted in a decrease of S100A14 mRNA and protein level. To characterize the RNA binding sequence recognized by SOX2, oligomer-directed RNase H digestion was coupled to the cross-linking before immunoprecipitation assay to demonstrate that SOX2 preferentially binds to the 3'-UTR of the S100A14 mRNA. Using EGFP-S100A14 3'-UTR reporters and mobility shift assay, we identified that the binding sequence on the 3'-UTR of the S100A14 mRNA exhibits a stem-loop structure. Together, our data indicates that SOX2 enhances S100A14 expression by binding to the 3'-UTR of the S100A14 mRNA. Functionally, depletion of SOX2 increases growth and mobility of BFTC905. Knock-down of S100A14 in BFTC905 also leads to an increase in the number of the cells in the S phase and higher mobility, suggesting that SOX2 suppresses cell growth and mobility through promoting the expression of S100A14. Together, our experimental evidence indicates that SOX2 is capable of exerting its cellular functions by functioning as an RNA binding protein in post-transcriptional regulation.
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PMID:SOX2 suppresses the mobility of urothelial carcinoma by promoting the expression of S100A14. 2895 11